Drum for intimately contacting gas and liquid



United States Patent Continuation of Ser. No. 411,232, Nov. 16, I964, abandoned.

[45] Patented Dec. 1,1970

[54] DRUM FOR INTIMATELY CONTACTING GAS AND LIQUID 8 Claims, 17 Drawing Figs.

[52] US. Cl 261/29, 261/83, 261/90 [51] Int.Cl B01d 47/18; B0lf3/04, B0lf9/02 [50] Id ofSearch 26l/83,84, 90, 91, 92, 89, 29; 233/l2l5; 55/230, 231, 232; 23/269 [56] References Cited UNITED STATES PATENTS 199,450 l/l878 Kirkham ct a1. 261/92 275,238 4/1883 Marcus 261/92 939,351 11/1909 Tillotson 261/90 1,379,831 5/1921 Lindauer 261/90 1,811,528 6/1931 Andrews et al.. 261/90 2,234,921 3/1941 Webb 233/15UX 2,281,616 5/1942 Placek 261/83 2,941,872 6/1960 Pilo etal... 26l/84X 3,179,333 4/1965 Claridge 233/15 FOREIGN PATENTS 386,089 l/l933 Great Britain 261/91 552,457 4/1943 Great Britain 261/92 Primary Examiner-Ronald R. Weaver Attorney-Sommer, Weber & Gastel ABSTRACT: A gas-liquidcontactapparatus including a hous- 9 ing air to pass into the housing and radially inwardly through the second apertures after contacting liquid on the fringe members which is flung radially outwardly through the first apertures. The perforated shell has inner and outer peripheral surfaces and first and second portions with the first portions interspersedwith the second portions. The first portions are located closer to the center of the shell than the second portions adjacent thereto. The first apertures are located in the second portions and the second apertures are located in the first portions. The first apertures are located radially outwardly of the second apertures to thereby cause liquid deposited on the inner peripheral surface of the shell to be forced radially outwardly through the first apertures by centrifugal force when the shell is caused to rotate to set up a spray of liquid about the outer peripheral surface. The forcing of the liquid through the first apertures tending to leave the second apertures free from liquid to permit the gas to pass radially inwardly through the shell. The liquid and gas do not tend to pass through the same apertures to thereby permit the counterflow relationship with a low pressure drop and elimination of carryover, In one embodiment the second portions of the shell extend in a helical path axially along the periphery of the shell. The liquid is deposited on theinside of the shell to be forced into those portions ofthe internal surface at the second portions of the shell and to be distributed equally throughout the portions of the internal surface of the shell by virtue of the continuity provided by the helical path. The fringe members are continuously elongated and a channel receives the base portion of the fringe members. The channel is of helical configuration in following the helical path of the second portion of the shell. The base of the fringe member is located in contiguous relationship to the first apertures to thereby convey liquid passing therethrough radially outwardly. The gas which passes radially inwardly is prevented from carrying discharged liquid therewith by a flap member which is attached to the conduit-for engaging the inner peripheral portion of the shell. The fringe members are removably secured to the shell to permit selective replacement. The helical path followed by the second portions of the she'llcons'titutes a first helical path and the second portions of the shell follows a second helical path lying parallel to the first helical path to provide a double thread arrangement. in.-

another embodiment the shell isformed with undulations and in which the first portionsof the shell are those portions of the undulations lying closer to the axis of rotation of the drum. The second portions of theshell are those portions of the undulations-lying more remote from the axis of the drum than the first portions.

Patented Dec. 1, 1970 Sheet gulp, 22

INVENTOR. Lawrence 77Zac7 ow Paiented Dec. 1, 1970 I 3,544,084

I NVEN'TOR.

Lark/F9726? 77?a crow WMw A TTOIPNES.

Patntd Dec. '1, 19,70 3,544,084

Sheet 3 of 5 INVENTOR.

ATTORNEY? Patented Dec. 1, 19 70 3,544,084

' Sheet 5 of 5 v INVEN TOR.

A3 Lawrence 77Zczc7'0w DRUM FOR INTXMATELY CONTACTING GAS AND LIQUID This application is a continuation of my US. Pat. application Ser. No. 411,232, filed Nov. 16, 1964 and now abandoned.

GAS-LIQUID CONTACT APPARATUS The present invention relates to an improved gas-liquid contact apparatus for effecting intimate mixing between a gas and a liquid without appreciable entraining of said liquid in said gas and without experiencing a substantial pressure drop in the gas passing through the apparatus.

In the past, gas-liquid contact apparatus has been utilized in various applications, such as gas cleaning and scrubbing, humidifying, dehumidifying and air conditioning. However, with prior types of apparatus, the more intimate the contact between the liquid and the gas, the greater was the tendency to carry over liquid with the gas and the tendency for relatively high pressure drops of the gas. The problem of carryover of the liquid with the gas gave rise to the need for eliminators for removing such carried over liquid from the gas with the expense attendant thereto which was reflected not only by the initial cost of such eliminators but also by its subsequent cost for maintenance. The relatively high pressure drops experienced by gases flowing through previous gas-liquid contact apparatus required additional costly pumping capacity for the gas. Furthermore, in the past in order to effect intimate mixing for certain applications, high pressure nozzles were required for directing the liquid into the gas. These high pressure nozzles were relatively costly. Furthermore, certain prior types of gas-liquid contact apparatus required frequent cleaning which, in turn, created additional expense. The present invention is concerned with an improved gas-liquid contact apparatus which overcomes the above noted deficiencies of the prior art in a simple and expedient manner.

lt is accordingly one object of the present invention to provide an improved gas-liquid contact apparatus which operates in an extremely efficient manner. A related object of the present invention is to provide an improved gas-liquid contact apparatus which effects intimate mixing between a liquid and a gas without the requirement for extremely high liquid pressures or expensive nozzles. A further related object of the present invention is to provide an improved gas-liquid contact apparatus which effects intimate mixing without carry over of the liquid in the gas. A further related object of the present invention is to provide an improved liquid gas apparatus which effects intimate contact between the liquid and the gas without an unreasonably high pressure drop of the gas passing through the apparatus.

Another object of the present invention is to provide an improved gas-liquid contact apparatus which causes the intimate mixing between a liquid and a gas and the resultant separation of the liquid from the gas in an extremely simple and expedient manner which is inherent in the design of the apparatus.

A further object of the present invention is to provide an improved gas-liquid contact apparatus which is capable of providing a triple zone mixing action to insure intimate mixing between said liquid and said gas. A related object of the present invention is to provide intimate mixing by violent intermixing of said liquid and said gas and in addition provide an extremely large area of surface contact therebetween.

A still further object of the present invention is to provide an improved liquid contact apparatus which is extremely efficient in operation in providing an extremely high rate of gasliquid contact so as to permit it to be made smaller and less costly than existing liquid gas contact apparatus of comparable capacities.

Another object of the present invention is to provide an improved gas-liquid contact apparatus which is capable of providing a highly efficient gas scrubbing action to remove impurities from the gas.

Yet another object of the present invention is to provide an improved gas-liquid contact apparatus wherein the intimate mixing between the liquid and the gas is accomplished in an extremely unique and simple manner by an arrangement which is self-cleaning so as to obviate the necessity for frequent cleaning of the apparatus due to clogging by impurities in the gas.

Still another object of the present invention is to provide an improved liquid gas contact apparatus consisting of a combination of a drum and a replaceable fringe member thereon which can be removed from the drum and replaced by another when the fringe unit becomes either worn or otherwise unserviceable. A related object of the present invention is provide a combination drum and fringe member in which the fringe member may be replaced by another fringe member having different operational characteristics to thereby permit the same drum to provide different characteristics when utilized with different fringe members. Other objects and attendant advantages of the present invention will be readily perceived hereafter. I

The present invention relates to an improved device for providing intimate gas-liquid contact with extremely low pressure drop of the gas and substantial elimination of carry over of liquid by said gas when the liquid and gas pass in counter flow relationship. The device includes a housing having a chambertherein with a drum mounted in the chamber. Means are provided for effecting rotation of the drum. The drum includes a shell having outer and inner peripheral surfaces. A liquid depositing arrangement is provided for depositing liquid on the inner peripheral surface of the shell. The shell includes first apertures extending from the inner surface toward the outer surface for transmitting the liquid from the inside of the drum to the chamber by virtue of the fact that the liquid is forced therethrough by centrifugal force when the drum is caused to rotate. The shell also includes second apertures extending from the outer surface to the inner surface thereof. Air moving means is provided for forcing the gas from the chamber to the inside of the drum through the second apertures. Outwardly extending fringe members are mounted on the outer surface of the shell in contiguous relationship to the apertures which pass liquid for providing a large surface area of contact between the liquid passing in a direction radially outwardly from the first apertures and the gas passing radially inwardly from the chamber to the inside of the drum through the second apertures. The fringe members include an infinite number of bristles which throw off sufficient liquid to create an extremely dense liquid barrier in the chamber to provide a first zone for gas-liquid contact and this first zone wets down a substantial proportion of the gas-borne solids and precipitates them to a collecting sump. Thereafter the gas passes to the outer edge of the fringe members and in contact therewith where a second zone is provided for effecting intimate and violent gas-liquid contact to thereby provide great intermixing and also separate other particles from the gas. Thereafter, the gas passes between the outer tips of the fringe members and the outer surface of the shell which provides a third zone for creating further extensive contact between the gas and the liquid whereby the subjecting of the gas to the three zones effects a high degree of contact between the liquid and the gas and also prevents the fringe members from becoming clogged with impurities or the like.

The improved gas-liquid contact device of the present invention includes a drum for passing the liquid and gas in counterflow relationship and a shell including first and second portions with the first portions interspersed with the second portions and the first portions being located closer to the center of the drum than second portions adjacent thereto. The above noted gas passing apertures are located in the first portions closer to the center of the drum and the liquid passing apertures are located in the second portions further from the center of the drum so that the liquid passing apertures are located generally radially outwardly of the gas passing apertures adjacent thereto. Therefore, liquid which is deposited on the inside of the drum is inherently forced by centrifugal force through the liquid passing apertures, thus leaving the gas passing apertures, located closer to the center of the drum, free for passage of gas radially inwardly in counterflow relationship to the liquid passing outwardly. The shell includes channels located on the outside thereof for receiving an elongated fringe member, the base of which is laid into the channels in contiguous relationship to the liquid passing apertures so that the liquid passing outwardly comes into contact and saturates the elongated bristles of the fringe members and thereby provides an extremely large surface area for liquid gas contact. The fact that liquid is caused to pass through one set of apertures and the faet that the gas is caused to pass through another set of apertures produces the above mentioned extremely low pressure drop because the liquid does not clog the apertures through which the gas must pass. Furthermore, the fact that the liquid and gas in essence pass through separate apertures obviates the tendency for entrainment of liquid in the gas.

The present invention will be more fully understood when the following portions of the specification are read in conjunction with the accompanying drawings wherein:

FIG. 1 is an elevational view, partially in cross section, of an improved gas-liquid contact apparatus made in accordance with the principles of the present invention; 7

FIG. 2 is a fragmentary cross-sectional detail view taken substantially along line 2-2 of FIG. 1 and oriented in a horizontal position, for the sake ofconvenience, and showing the manner in which the outer surface of the drum is formed and the relationship of the fringe thereto;

FIG. 3 is a fragmentary view taken substantially along line 3-3 of FIG. 1 and showing the various gas-liquid contact zones which are provided by theinstant apparatus;

FIG. 4 is an elevational view of a portion of the elongated fringe which is wound on the outer periphery of the drum;

FIG. 5 is an alternate modification of the fringe of FIG. 4 with the bristles being corrugated rather than straight, as in FIG. 4;

FIG. 6 is an alternate modification of the improved gasliquid contact apparatus of the present invention and showing a frustoconical drum instead of a cylindrical drum, such as shown in FIG. 1;

FIG. 7 is a fragmentary elevational view partly in cross section showing an alternate modification of a drum structure with the convolutions being in the form of rings rather than of a helical. shape such as shown in FIG. 1;

FIG. 8 is a view takensubstantially along line 8-8 of FIG. 7 and showing a form of liquid feeding manifold which can be used in the embodiment of FIG. 7;

FIG. 9 is a detail view showing the manner in which the drum of FIG. 1 can be stabilized for highspeed operation;

FIG. 10 is a view taken substantially along line 10-10 of FIG. 1 and showing the construction of the liquid inlet manifold;

FIG. 11 is a detail view taken substantially along line 11-11 of FIG. 10;

FIG. 12 is a detail view showing the manner in which the opposite ends of the replaceable fringe may be mounted on and secured to the drum;

FIG. 13 is a schematic view of gas-liquid contact apparatus utilizing a plurality of drums in series, each constructed in accordance with the present invention to effect an extremely efficient gas scrubbing action; 1

FIG. 14 is an alternate form of drum structure;

FIG. 15 is still another form ofdrum structure;

FIG. 16 represents still another form of drum structure and is taken along line 16-16 ofFlG. 17; and

FIG. 17 is a view taken substantially along line 17-17 of FIG. 16.

In FIG. 1 the improved gas-liquid contact In FIG. 1 the improved gas-liquid contact apparatus of the present invention is shown. A substantially cylindrical washing chamber is provided having a housing 11 with an imperforate end wall 12 at one end and a circular opening 13 at the other end. Housing 11 is mounted on base 14 which also mounts electric motor 15. A pulley 16 which is keyed to the output shaft of motor 15 is encircled by belt 17 which also encircles pulley 18 mounted on shaft 19 which in turn is journaled for rotation in bearings 20 and 21 held in cylindrical tube 22 having one end abutting end wall 12 and the other end proximate pulley 18. A plurality oftriangular plates 23 are welded to end wall 12 and to the outside of tube 22 to support the latter.

The end of shaft 19 which is remote from pulley 18 has the imperforate circular end plate 24 of drum 25 fixedly mounted thereon in a cantilevered supporting relationship. An annular plate 26 is mounted at the end of drum 25 remote from plate 24 and has laterally extending annular flange 27 thereon which receives one end of gas conducting conduit 28 within its confines. A sealing member 29 has one portion securely affixed to flange 27 and the other end 30 in sliding engagement with conduit 28 to provide a seal to prevent leakage of gas flowing through conduit 28. Seal 29 may be made of flexible rubber sheet or any other material which will provide a good sealing relationship. A spider 31 is mounted in the end of conduit 28 remote from drum 25 and supports bearing 32 which in turn journals shaft 33 which mounts fan 34, shaft 33 also mounting pulley 35 which is encircled by belt 36 which also encircles pulley 37 mounted on the shaft of motor 38.

Gas which is admitted to the inside of housing 11 through opening 13 passes radially inwardly through drum 25 and then through conduit 28 as a result of the action of fan 34. Liquid is deposited on the inside of drum 25 and passes outwardly through the drum, in a manner to be described in detail hereafter, to effect a counterflow relationship with respect to the gas. More specifically, a sump 39 is located at the bottom of housing 11 for storing liquid 40 which is maintained at a predetermined level in sump 39 by valve 41 controlled by float 42, valve 41 being associated with conduit 43 leading from a suitable liquid source. A circulating pump 44 is in communication with one end of conduit 45, the other end of which is in communication with sump 39. The outlet of pump 44 is in communication with conduit 46 which in turn is in communication with manifold 47 located on the inside of drum 25 FIGS. 1 and 10). It can thus be seen that liquid which is pumped by pump 44 will be moved from sump 39 to manifold 47 from which it is deposited on the inside of drum 25. Conduit 46 may lead to a suitable device for heating or cooling the liquid prior to delivering to header 47, depending on the function to be performed by the liquid.

The gas-liquid contact drum 25 possesses an unique construction which causes it to pass the gas and liquid in counterflow relationship therethrough without a substantial carry over of the liquid with the gas and without causing a substantial pressure drop of the gas passing through the drum while providing an extremely high degree of contact between the gas and the liquid. In the embodiments of FIGS. l3 the drum 25 includes a generally cylindrical shell 25' which is constructed of continuous channels 48 and 49, each of which are wound to define a helix, and each of which alternate with the other to in effect provide a structure which is analogous to a double thread. The helical winding can be appreciated from FIG. 1. The channels 48 when taken in combination with channels 49 show the surface of the shell 25' to in effect be formed with a series of convolutions or undulations with first portions of the shell being located closer to its center of rotation than second portions.

During fabrication, the channels 48 and 49 are wound on a form and then brazed or otherwise secured to each other to form an integral unit. If it is desired to make the shell 25' of drum 25 extra stiff, the rods 27' (FIG. 9) may be provided between end plate 24 (which is analogous to plate 24 of FIG. 1) and end plate 26 (which is analogous to end plate 26 of FIG. 1).

While the drum is being driven by motor 15 through the above described linkage, pump 44 operates to deposit water onto the inner peripheral surface of shell 25' proximate the lower portion of the shell which is horizontally mounted as shown in FIG. 1. To this end, liquid distributing manifold 47 has an elongated slot 50 which runs for substantially the entire length thereof and the water which passes through slot 50 is pumped at a very low pressure, in the range of l or 2 inches of water, and is essentially laid into the channels 54 (FIG. 2) which are formed by the contiguous surfaces 48' and 49' of channels 48 and 49, respectively (see FIG. 2). In other words, while the water is deposited on the inside surface of the shell, it will tend to move downwardly by gravity into the channel created by the above mentioned surfaces 48 and 49' of channels 48 and 49, respectively. A splash flap 51 FIGS. and 1]) extends from manifold 47 and has one end affixed thereto and has the other end in contact with the inside of shell Flap 51 has slits 52 at end 53 thereof and these slits cause flap 51 to very closely follow the contour of shell 25'. It will be noted from FIG. 10 that drum 25 rotates in the direction of the arrow and slot 50 of manifold 47 deposits water in a manner which may be termed opposite to the direction of rotation'of drum 25. This has been found to cause the liquid to be received on the. inner peripheral surface of the drum and causes it to lay down rapidly with a minimum of splashing. However, to avoid any subsequent splashing, flap 51 prevents the liquid on the inner peripheral surface of drum 25 from being carried inwardly by the air stream passing through the drum, in a manner to be described hereafter, before it is forced into the above described channels 54 and held there by the centrifugal force produced by the rotating drum.

After the liquid is deposited in the above described manner, it will form reservoir 54' in channels 54 which are formed by contiguous outer surfaces 48' and 49' of channels 48 and 49, respectively. Channels 48 and 49 are perforated. Channels 48 have apertures 55 therein and channels 49 have apertures 56' therein. Apertures 55' and 56' were originally in the metal stock from which the channels were fabricated by a rolling operation or the like. However, it will be appreciated that most of the apertures of the sidewalls of each of channels 48 and 49 are blocked by the solid portions of the sidewalls of the adjacent channels joined thereto so that there will be in effect one solid sidewall where the sidewalls of each of the channels are joined. However, the apertures 56' in the rounded portion of channels 49 will remain open and the apertures 55' in the rounded portion of channels 48 and in part of the straight sidewall will remain open inasmuch as the sidewalls of the channels 48 and 49 do not obstruct each other in this area.

As noted above, the rotation of drum 25 will cause the water to deposit in channels 54 and this liquid will stay there because of the centrifugal force due to such rotation. Liquid receiving channel 54 in shell 25' is helical and therefore provides for a self-feeding action. In this respect, if there is any excess of liquid deposited in any portion of this continuous channel 54, it will tend to flow to other portions which have less liquid so that uniform delivery of liquid to the outside of the drum is always assured. The centrifugal force due to rotation will force the liquid through apertures 56', while leaving apertures 55' in the curved portion of channel 48 unobstructed by liquid. Thus, liquid will pass outwardly through apertures 56' in channels 49 in counterflow relationship to the gas passing inwardly through apertures 55' in channels 48. Liquid passing apertures 56' are provided in portions of the shell 25 which. are more remote from the center of the drum than other portions in which gas passing apertures 55' are located, and it is the centrifugal force exerted on the liquid in channels 54 which keeps the liquid passing apertures 56' supplied with liquid while permitting the gas passing apertures 55' to remain clear for the passage of gas. It is to be noted from FIG. 2 that certain of the apertures in channels 48 are in a zone wherein the liquid from channels 54 can pass therethrough into the inside of channels 48 through which the aii-must pass radially inwardly. It would therefore appear that such liquid would be entrained in the gas and be carried through apertures 55" with it. However, this is not the case because drum Z5 is rotating at a rapid rate and the area of apertures 55 is relatively small as compared to the area of the solid portions of channels 48. Thus, the probability of droplets of water passing through apertures 55 is very small and in fact substantially nonexistent, especially since the drum is rotating at a rapid rate. Thus, the liquid which is entrained in the air within channels 48 will strike the solid portions of channels 48 and therefore be subjected to the centrifugal force of the rotating drum and be forced outwardly against the force of the incoming gas.

It should be noted that storage capacity in the channel 49 holding the fringe member 57 (to be described in detail hereafter) is significant. Even under the centrifugal forces generated, capillary forces in the small spaces comprising the fringe itself as well as the small passage in which it is confined tend to hold up liquid which then leaks off gradually along the individual fibers. Thus, a supply of liquid tends to be maintained until it is replenished as a given point approaches the header.

In addition to the foregoing phenomenon, it is to be noted that any liquid within channel 48 which has passed into it through those apertures 55' in channel 54 which are in contact with the liquid will rotate with the drum and therefore be subjected to the centrifugal force of such rotation and this centrifugal force is greater than the force of the air passing inwardly through channel 48. Therefore, while the air may pass radially inwardly because of the action of fan 34 (FIG. I), the liquid will not be entrained therein but will be separated therefrom.

It will be appreciated that shell 25' of drum 25 operating by itself in accordance with the above described theory of operation will be capable of providing excellent counterflow gasliquid passage without entrainment of the liquid in the gas. However, in addition to the foregoing structure of shell 25 a fringe is provided for a plurality of purposes. Firstly, the fringe consisting of a great number of bristles (each having an outer surface) wound in a substantially helical path on the outer surface of shell 25 by following channel 49 provides an extremely large surface area for providing gas-liquid contact while the gas and the liquid pass in counterflow relationship through the drum. Secondly, the fringe provides a violent mixing action. Thirdly, the fringe provides an additional filtering action on the gas.

The fringe which is utilized in the embodiments of FIGS. 1- -3 consists of round polypropylene bristles 56 in clusters 58 which are bent into U-shape and secured in a woven condition by nylon fibers 59. The bristles 56 are formed in an elongated fringe member 57 and the base 60 thereof is laid into channels 49 in the manner shown in FIG. 2. One end of the elongated fringe member is secured in channel 49 by nut and bolt arrangement 61 (FIG. 12) and the fringe member is wound in a path defined by helical channel 49 so that it substantially covers the entire outer surface of drum 25, and the opposite endiof fringe member 57 is secured to the portion of channel 49 remote from the opposite end by nut and bolt 62, or by any suitable clamping member.

As can be seen from FIG. 4, grommets 58' are provided at theends of the fringe member for the purpose of receiving bolts61 of FIG. 12 to thereby insure a firm locking engagement between the drum and the base 60 of the fringe unit 57. Additional fastening means such as grommets 58 may be positioned intermediate the ends of the fringe unit. In addition it is to be noted that spaces 59 are provided between the polypropylene bristles and the thread provided by nylon fibers 59. These spaces permit the bridging by the liquid which is supplied to base 60 to thereby enhance the retention of such liquid and insure a supply which is forced outwardly by centrifugal force along bristles 56. If desired, other liquid retaining material may be utilized to insure the existence of liquid at base 60 for transmission to bristles 56.

It can thus be seen that elongated fringe member 57 is held on the outer surface of drum,25 in an extremely simple and efficient manner. Furthermore, the base portion 60 of the elongated fringe member 57 lies in contiguous relationship to liquid passing aperture 56 in channel 49. Thus, the liquid which is forced outwardly through such liquid passing apertures 56 by centrifugal force will move into contact with the base 60 of elongated fringe member 57 and then move outwardly along the outer surfaces of each of the bristles 56 which are shown in FIG. 2 and which are tied in the above noted clusters 58. While the clusters tend to retain their identity near the base 60 of the elongated fringe member, the outer ends of the bristles 56 after having been whipped about will spread apart at the outer periphery of drum 25. The spacing between successive turns of the fringe unit and the density of the bristles in the fringe may be varied for different operational requirements. In FIG. 2 the spacing between adjacent turns of fringe is exaggerated for the sake of illustration. However, it will be appreciated that the successive turns merge with each other toward the outer edges 63 of the fringe.

Thus, a construction is provided wherein the liquid which passes outwardly by centrifugal force along each individual bristle forming a part of the fringe is exposed to the air passing inwardly and as drum 25 rotates. A violent mixing, atomizing, and intermingling action will be effected between the large surface area of liquid passing outwardly along bristles 56 and the gas passing inwardly. Furthermore, because the liquid is distributed into thin film on each of the bristles rather than remaining in droplets during the passage of the liquid from base 60 of the fringe members to outer edge 63 (FIG. 4), there is all the less tendency for the gas passing inwardly along the bristles to entrain such liquid.

It is to be noted at this point that while bristles 56 have been indicated as being made of polypropylene fibers, the same action may be obtained by the use of other plastic fibers or even by the use of cotton fibers or any other fibers which can withstand the centrifugal forces without breaking up. If real soft fibers, such as cotton fibers are utilized, then it will be observed that the centrifugal force of drum rotation will cause such fibers to stand up radially and not mat down, as would be the case if there were no rotation. Thus, the hardness or stiffness of the fibers themselves is not a factor to be considered too heavily in the design of the drum. It is to be further noted that the bristles may also be fabricated out of stainless steel or other metals or ceramics for applications wherein the gasliquid interchange is effected in atmospheres where corrosion is a factor to be considered or where high temperatures are to be considered. In short, the bristles may be made of any suitable material.

In FIG. 5, an alternate form of bristles is shown wherein bristles 156 are of an undulating or corrugated nature rather than straight as shown in FIG. 4. Otherwise, the fringe member 57' is identical to that shown in FIG. 4.

From the preceding portion of the description it can be seen how the liquid and gas pass in counterflow relationship without substantial entrainment of the liquid in the gas and without a substantial pressure drop because the gas passing through apertures 55 is not obstructed by liquid. As noted above, the air which enters housing 11 eventually is caused to pass through drum 25. However, before doing so it passes through an extremely dense concentration of water 64 which is in the portion of the chamber within housing 11 surrounding the outer edges of fringe 57. This zone is extremely dense with liquid because the water which passes outwardly along bristles 56 is discharged from an infinite number of bristle tips 63 into a zone designated in FIG. 3 as zone 1.

The reason that an extremely dense pattern of liquid is obtained in zone 1 is because the liquid will tend to be driven from the ends of the bristles in a manner which is generally tangential and it will be thrown off in an infinite number of droplets from the outer tips-of the bristles. Thus, while the droplets will tend to go in the same general direction from each of the bristles, the fact remains that the bristles are oriented in a circle so that the simultaneous throwing off of water from circularly-located rapidly rotating bristles will set up the above described dense pattern. In addition, a certain amount of the droplets will rebound from the inner surface of housing 11 and also increase the density of the liquid in zone 1.

Thus, a gas containing impurities therein, such as smoke particles or lint or any other foreign matter, is initially subjected to the extremely dense liquid in zone I and a large percentage of such impurities will be scrubbed or removed from the gas and will eventually settle in sump 39 from which they can be filtered by suitable filters, not shown. If any impurities are able to penetrate through the extremely dense liquid in zone 1, they will be subjected to a violent beating and centrifugal action in zone 2 where the outer edges of the fringe engage the gas passing inwardly through the bristles. This violent mixing and beating action tends to permit only the gas to pass inwardly while rejecting the impurities in the gas, assuming that such impurities are heavier than the gas. If any of the impurities move inwardly on the portions of fringe 57 between the outer edges and the base thereof, they will be subjected to the filtering action of the extremely densely situated bristles 56 and also to the centrifugal action of the liquid passing outwardly along the bristles, all this occurring in zone 3 shown in FIG. 3. Thus, the action of the bristles on drum 25, when considered in conjunction with the counterflow action of the liquid and the gas, as described above, provides a three-zone type of washing, scrubbing and mixing action between the liquid and the gas so that impurities in the gas are rejected and an extremely high degree of liquid gas contact is obtained.

It is to be especially noted that the foregoing action between the liquid and the gas causes the bristles to be essentially selfcleaning because the liquid coverage of the bristles coupled with the centrifugal force to which the liquid is subjected substantially prevents any of the impurities from being deposited on the bristles. Thus, the bristles are self-cleaning.

In addition, the large amount of liquid passing through the apparatus causes the inside of the drum to be constantly wetted thereby minimizing the tendency for the deposit of carbonates within the drum and on the bristles;

In FIG. 6 an alternate form of drum 67 is shown. This drum is of frustoconieal configuration and is installed in a system including a gas inlet conduit 65 leading to housing 66 in which drum 67 is mounted for rotation. A motor 68 is provided having pulley 69 which is encircled by belt 70 which in turn encircles pulley 71 affixed to a spider 72 of drum 67. Pulley 71 is journaled for rotation on liquid pipe 73 which is supported from the inside of housing by standard 74 at one end and by standard 75 at the other end. Bearings 76 affixed to the inside of drum 67 by spiders 72 and 77 mount drum 67 for rotation. Cap 77' prevents the air moving in conduit 65 from entering the small end of the frustoconieal drum 67, but forces it to pass in the direction of the arrows shown in FIG. 6. A fan 77" mounted in outlet conduit 78 is driven by motor 68 through belt 79 encircling pulleys 80 and 81, the latter being mounted on shaft 82 journaled in bearing 83 mounted on standard 84-. Water inlet to drum 67 is from conduit 85 leading to conduit 73. A suitable pump, not shown, is utilized. A conduit 73 in turn has conduits 86 leading therefrom in communication with manifold 87 which is in contiguous relationship to the inner surface of drum 67. The advantage of using a frustoconieal drum lies in the fact that the air exit velocity from drum 67 into conduit 78 is slower than obtained from a cylindrical drum of the same length having the same surface area. Likewise, this provides a greater cross-sectional area surrounding the smaller end of the drum for entry of the gas to be treated. This improves gas distribution and permits the casing to be smaller for a given volume of gas to be treated. The construction of drum 67 may be identical to that described above with respect to drum 25 of the embodiment of FIGS. 15, the only difference between the drum 25 of FIGS. 1--5 and FIG. 6 residing in the fact that one is cylindrical while the other is frustoconieal. In addition, it will be appreciated that the drum may be of any other suitable cross-sectional configuration which will provide the desired results.

In FIGS. 7 and 8 an alternate form of drum construction is shown. In this construction the drum 90 is formed with convolutions or undulations whiThTie in the form of rings around the periphery of the drum rather than running in a helix. A drum of this type may be made by a suitable metal rolling process. This drum has a shell 91 having perforations 92 therein. The drum is formed so that convolutions 93 and 94 lie a further distance from the center of the drum than convolutions 95. Thus, liquid will be forced by centrifugal force into channels 96 lying between adjacent convolutions 95 and will tend to leave the drum through certain of apertures 92 while gas will pass inwardly into the drum through outer channel 97 and through apertures 92 therein which are not obstructed by liquid. The ring construction shown in FIGS. 7 and 8 may be utilized in conjunction with either the cylindrical drum shown in FIGS. 1-5 or the frustoconical drum shown in FIG. 6. The elongated fringe member 57 utilized in conjunction with the embodiment of FIGS. 7 and 8 may be of the identical construction described above with respect to FIGS. 15. It is to be noted, however, that since the fringe receiving channels 94' are in the form of rings, the opposite ends of the elongated fringe 57 in each channel must be joined to each other and this may be effected by suitable clips or the like. If desired, the convolutions or undulations of the embodiment shown in FIG. 7 may run in a helix.

In the embodiment of FIGS. 7 and 8 a different type of liquid feeding arrangement is shown for use with the'ring type of construction. More specifically, a liquid feeding manifold or header 98 is provided which runs the length of the drum and extends substantially parallel to the axis of rotation thereof. A series of nipples 99 extend from manifold 98 with the outlet ends 100 thereof being located within channel 96. Because the liquid is laid into the liquid receiving channels 96 by the use of nipples 99, the need for additional structure is minimized for preventing said liquid from splashing prior to the time that it is forced into engagement with the inner surface of the drum by centrifugal force.

It will be appreciated that because of the simplicity of installation and removal of the continuous fringe member 57 of FIGS. 14, fringe members having different characteristics, that is, with different lengths and thicknesses of bristles may be interchangeably applied to the shell 25'.

The liquid-gas contact apparatus of the present invention has been described in a general vein as beingapplicable to any purpose for which it may be utilized and the liquid may be any liquid including water and the gas may be any gas including air. There are various applications for the instant apparatus and such applications include its use in evaporative coolers of the industrial type, such as used in textile mills in all climates and in all types of buildings, in factories, steel mills and forge shops having highly concentrated high-level heat loads. In addition, the instant apparatus with suitable design may be'utilized in humidifiers for all applications, including residential. Furthermore, as will be readily appreciated, the instant apparatus has usage in cooling towers in industrial water coolers. In addition, the instant apparatus may be utilized in the humidifiers and air conditioners in all types of buildings in which it is practical to use open water systems. especially in large one-story buildings. In all the foregoing applications the liquid is water and the gas is air. The apparatus of the present invention can also be utilized in liquid gas interchanges for chemical plants or refineries in all other complexes requiring interchange of heat between other types of gases and liquids. The interchangers can be built entirely of stainless steel or other materials suitable for this duty and for such applications the bristles instead of being plastic, as described above, may be made out of stainless steel or other noncorrosive material including ceramics, glass, and glass fibers. The instant apparatus is also capable of use as a self-cleaning filter and gas purifier when only the filtering function is required. The fringe members may be flooded with a nonhygroscopic fluid or water and also may be designed for any reasonable efiiciency which is desired. The fluid which may be utilized may also be a chemical which contributes to air purification and sterilization in view of the intimate mixing of liquid and gas at said relatively high efficiency which insures that the gas passing through the purifier is projected into substantially a 100 percent contact with the liquid therein.

In FIG. 13 an alternate form of the present invention is shown wherein frustoconical drums 101 and 102, made in accordance with the principles of the present invention, are located within conduit 103 which is fed by conduit 104. Shaft 105 is journaled in bearings 106 and 107 and said shaft mounts suitable spiders, not shown, which support drums 101 and 102 at their opposite ends. A motor 108 drives belt 109 which encircles pulley 110 fixed to shaft 105 to thereby rotate drums 101 and 102. Seal 111 separates chamber 112 from 113 so that gas passing into chamber 112 from conduit 104 must pass through drum 101. Thereafter the gas passes into chamber 113 and it must pass through drum 102 because of the existence of seal 114. The gas then passes into conduit 115 as a result of being moved into said conduit by fan 116 mounted on shaft 105. The apparatus of FIG. 13 is especially useful in scrubbing gas to remove foreign particles therefrom. In this embodiment drum 101, which may be identical in all respects to the drum described above with respect to FIG. 6, will take out a large percentage of the impurities and drum 102 will take out the same percentage of the remaining impu rities of the initially purified gas. Although not shown, the arrangement for depositing liquid on the insideof drums 101 and 102 may be similar to that disclosed above with respect to FIG. 1, or else the structure may be modified so that the liquid depositing arrangement is similar to that shown in FIG. 6.

In FIG. 14, an additional type of drum construction is shown which is constructed in accordance with the principles of the present invention. This drum includes a shell 116 having a plurality of first outwardly punched or drawn portions 117 and a second plurality of inwardly punched or drawn portions 118. Apertures 119 are at the peaks of outwardly extending portions 117 and apertures 120 are at the peaks of inwardly extending portions 118. It will readily be appreciated that liquid deposited within drum 116 will tend to move into the depressions on the inside of outwardly extending portions 117 and leave through holes 119. Furthermore, since portions 118 extend inwardly toward the inside of the drum, the apertures 120 therein will not receive the water on the inside of the drum and therefore be free for the passage of gas. The outwardly extending projections 117 and the inwardly extending projections 118 may be oriented relative to each other in any desired configuration and, if desired, portions 117 may be in the form of helical tracks and the fringe unit may be wound between such portions to define a helix and the air passing apertures may alternate with those liquid passing apertures in the same manner described above with respect to FIG. 1. In this embodiment, the nonapertured portion of the drum acts as a channel for conducting liquid to apertures 119.

In FIG. 15 a still further embodiment of the present invention is shown wherein the surface of the drum is formed of convolutions having apertures 121 at the bases of the convolutions and apertures 122 at the peaks of the convolutions or undulations. The apertures 122 are formed by striking up triangular-shaped projections from the peaks of the convolutions and a continuous fringe having a base portion 123 and bristle portions 124 is impaled on said peaks 123 to thereby retain said fringe in operating position.

In FIGS. 16 and 17 a still further form of the present invention is shown wherein drum 126 has convolutions or undulations 127 extending longitudinally of the axis of the drum. Upstanding ears 128 are located at the ends of the convolutions and a bar 129 is received in alined apertures, not numbered, in opposed pairs of ears 128. A fringe unit 130, which may consist bf bristles 131 fastened to each other along a line which is located in underlying relationship to bar 129, will hold said fringe member in assembled relationship. The bristles 131 may be fastened to each other by suitable weaving and each bar 129 will hold each fringe unit 130 in place. In this embodiment each fringe unit may be removed by removing bar 129 from apertures in ears 128. Suitable nuts 129 may be threaded on the ends of rod 129 to secure it to ears 128. Gas passing apertures 132 are provided in the portions of the undulations closest to the center of the drum and liquid passing apertures 133 are located immediately under fringe unit 130.

In the preceding embodiments, continuous fringe members have been shown for effecting the intimate gas-liquid contact on the outside of the drum. It will be appreciated, of course, that if desired individual tufts may be inserted through the liquid passing apertures and suitable secured therein as by keying while permitting sufficient clearance between said tufts and liquid passing apertures for the passage of liquid radially outwardly. It will therefore be appreciated that the term fringe members as used in the present disclosure includes individual tufted members or clusters thereof.

1 claim:

1. A drum for use in a device which provides intimate gasliquid contact with a low pressure drop of said gas and elimination of carry over of said liquid by said gas when said liquid and said gas pass in counterflow relationship through said drum comprising a perforated shell having inner and outer peripheral surfaces and first and second portions with said first portions interspersed with said second portions and said first portions being located closer to the center of said shell than second portions adjacent thereto, gas passing apertures in said first portions, liquid passing apertures in said second portions, said liquid passing apertures being located radially outwardly of said gas passing apertures adjacent.

thereto to thereby cause liquid deposited on said inner peripheral surface of said shell to be forced radially outwardly through said liquid passing apertures by centrifugal force when said shell is caused to rotate to set up a spray of liquid about said outer peripheral surface, said forcing of said liquid through said liquid passing apertures tending to leave said gas passing apertures free from said liquid to permit said. gas to pass radially inwardly through said shell whereby liquid and gas do not tend to pass through the same apertures to thereby permit said counterflow relationship with a low pressure drop and elimination of said carry over, said second portions of said shell extending in a helical path axially along the periphery of said shell to thereby cause liquid which is deposited on the inside of said shell to not only tend to be forced into those portions of said internal surface at said second portions of said rotation, gas moving means for moving said gas into said shell but also to tend to be distributed equally throughout said 7 portions of said internal surface at said second portions of said shell by virtue of the continuity provided by said helical path, elongated bristles formed in a continuous elongated fringe member having a base portion with said bristles attached thereto and extending outwardly therefrom, and means for receiving said elongated bristles of said fringe member including a channel in which said base portion of said fringe member is laid, said channel being of helical configuration in following said helical path of said second portions of said shell, said base of said fringe member being located in contiguous relationship to said liquid passing apertures to thereby convey liquid passing therethrough radially outwardly.

2. A drum as set fourth in claim 1 including means at spaced locations on said shell for removably securing said fringe member thereto to permit selective replacement thereof.

3. A drum as set forth in claim 2 wherein said helical path followed by said second portions of said shell constitutes a first helical pate and wherein said second portions of said shell follow a second helical path lying parallel to said first helical path to provide a double thread arrangement.

4. A device for providing intimate gas-liquid contact with a low pressure drop of said gas comprising a stationary housing providing a chamber, a drum in said chamber including a shell having an inner peripheral portion and an outer peripheral portion with openings extending therebetween, bristle means chamber and causing said as to ass from said chamber into said drum inwardly throug sal bristle means and through said openings in a direction from said outer peripheral portion toward said inner peripheral portion, stationary conduit means within said shell having outlet means for discharging liquid including means extending outwardly from said conduit means in contiguous relationship to said shell for preventing gas passing radially inwardly from said inner peripheral portion from carrying said discharged liquid therewith by laying said liquid directly onto said inner peripheral surface, and means for rotating said drum at a speed which will cause the liquid which is deposited onto said shell to be subjected to the centrifugal force of rotation and therefore be flung outwardly onto said chamber after having passed radially outwardly along said bristle means without being carried into the inside of said drum by gas passing inwardly through said bristle means and said openings, said conduit means depositing said liquid on said shell in an amount which will thoroughly wet said fiber means and provide an excess which leaves said fiber means due to said centrifugal force of rotation of said drum to provide a spray of liquid within said chamber between said drum and said housing to provide a first zone for effecting contact with the gas in said chamber, said bristle means being located in contiguous relationship to and overlying said openings in said shell so that said gas passing through said openings from said chamber must also pass through said bristle means and in contact with said liquid on said bristle means to provide a second zone for effecting intimate contact with the liquid thereon after having experienced intimate contact with said spray in said chamber.

5. A device for providing intimate gas-liquid contact as set forth in claim 4 wherein said bristle means comprises an elongated fringe member having a base portion and bristles extending outwardly therefrom, said fringe member being wound on said outer peripheral portion in a helical path, and fastening means for securing said fringe member to said shell.

6. A device for providing intimate gas-liquid contact as set forth in claim 4 wherein said means for preventing gas passing radially inwardly from carrying discharged liquid therewith comprises a flap member attached to said conduit means for engaging said inner peripheral portion of said shell.

7. A device as set forth in claim 4 wherein said shell includes first and second portions adjacent to each other, said first portions being interspersed with said second portions and said first portions being located closer to the axis of rotation of said drum than the second portions adjacent thereto, said openings comprising gas passing aperture means located in said first portions and liquid passing aperture means located in said second portions whereby the liquid passing aperture means are located radially outwardly of the gas passing aperture means adjacent thereto so as to thereby cause liquid deposited on the inner surface of said shell to be forced radially outwardly through the liquid passing aperture means by centrifugal force when said drum is rotated, the forcing of the liquid through said liquid passing aperture means leaving the gas passing aperture means free from liquid to permit the gas to pass radially inwardly through the drum without entraining the liquid.

8. A device as set forth in claim 7 wherein said shell is formed with undulations and in which said first portions of the shell are those portions of the undulations lying closer to the axis of rotation of the drum and in which said second portions of the shell are those portions of the undulations lying more remote from the axis of the drum than the first portions. 

